Add from_base32 presto function

velox/common/encode/tests/Base32Test.cpp

@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include "velox/common/encode/Base32.h"
+#include <cstring>
+
+namespace facebook::velox::encoding{
+
+constexpr Base32::ReverseIndex kBase32ReverseIndexTable = {
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 26,  27,  28,  29,  30,  31,  255, 255, 255, 255,
+  255, 255, 255, 255, 255, 0,   1,   2,   3,   4,   5,   6,   7,   8,   9,
+  10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  23,  24,
+  25,  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
+  255};
+
+// Test cases for Base32::calculateDecodedSize
+TEST(Base32Test, CalculateDecodedSizeEmptyInput) {
+  std::string_view input = "";
+  size_t inputSize = 0;
+  size_t decodedSize = 0;
+
+  auto status = Base32::calculateDecodedSize(input, inputSize, decodedSize);
+  EXPECT_TRUE(status.ok());
+  EXPECT_EQ(decodedSize, 0);
+}
+
+TEST(Base32Test, CalculateDecodedSizePaddedInput) {
+  std::string_view input = "MY======";  // Base32 encoded "f"
+  size_t inputSize = input.size();
+  size_t decodedSize = 0;
+
+  auto status = Base32::calculateDecodedSize(input, inputSize, decodedSize);
+  EXPECT_TRUE(status.ok());
+  EXPECT_EQ(decodedSize, 1);  // "f" is 1 byte
+}
+
+TEST(Base32Test, CalculateDecodedSizeUnpaddedInput) {
+  std::string_view input = "MZXW6YTBOI======";
+  size_t inputSize = input.size();
+  size_t decodedSize = 0;
+
+  auto status = Base32::calculateDecodedSize(input, inputSize, decodedSize);
+  EXPECT_TRUE(status.ok());
+  EXPECT_EQ(decodedSize, 6);
+}
+
+// Test cases for Base32::base32ReverseLookup
+TEST(Base32Test, Base32ReverseLookupValidChar) {
+  Status status;
+  uint8_t result = Base32::base32ReverseLookup('M', kBase32ReverseIndexTable, status);
+  EXPECT_TRUE(status.ok());
+  EXPECT_EQ(result, 12);
+}
+
+TEST(Base32Test, Base32ReverseLookupInvalidChar) {
+  Status status;
+  uint8_t result = Base32::base32ReverseLookup('@', kBase32ReverseIndexTable, status);  // '@' is not in Base32 charset
+  EXPECT_FALSE(status.ok());
+  EXPECT_EQ(result, 0);
+}
+
+// Test cases for Base32::decodeImpl
+TEST(Base32Test, DecodeImplValidInput) {
+  std::string_view input = "MZXW6YTBOI======";
+  size_t inputSize = input.size();
+  char output[6] = {0};
+  size_t outputSize = sizeof(output);
+
+  auto status = Base32::decodeImpl(input, inputSize, output, outputSize, kBase32ReverseIndexTable);
+  EXPECT_TRUE(status.ok());
+  EXPECT_STREQ(output, "foobar");
+}
+
+TEST(Base32Test, DecodeImplInvalidInputLength) {
+  std::string_view input = "MZXW6";
+  size_t inputSize = 3;
+  char output[5];
+  size_t outputSize = sizeof(output);
+
+  auto status = Base32::decodeImpl(input, inputSize, output, outputSize, kBase32ReverseIndexTable);
+  EXPECT_FALSE(status.ok());
+}
+
+TEST(Base32Test, DecodeImplOutputBufferTooSmall) {
+  std::string_view input = "MZXW6YQ=";  // Base32 encoded "foobar"
+  size_t inputSize = input.size();
+  char output[3];  // Too small for decoded output
+  size_t outputSize = sizeof(output);
+
+  auto status = Base32::decodeImpl(input, inputSize, output, outputSize, kBase32ReverseIndexTable);
+  EXPECT_FALSE(status.ok());
+  EXPECT_EQ(status.message(), "Base32::decode() - output buffer too small.");
+}
+
+}

velox/common/encode/tests/CMakeLists.txt

@@ -12,7 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-add_executable(velox_common_encode_test Base64Test.cpp EncoderUtilsTests.cpp)
+add_executable(velox_common_encode_test Base32Test.cpp Base64Test.cpp
+                                        EncoderUtilsTests.cpp)
 add_test(velox_common_encode_test velox_common_encode_test)
 target_link_libraries(
   velox_common_encode_test

velox/docs/functions/presto/binary.rst

@@ -63,6 +63,28 @@ Binary Functions
 
     Decodes ``bigint`` value from a 64-bit 2’s complement big endian ``binary``.
 
+.. function:: from_base32(string) -> varbinary
+
+    Decodes a Base32-encoded ``string`` back into its original binary form.
+    This function can handle both padded and non-padded Base32 encoded strings. Partially padded Base32 strings will result in an error.
+
+    Examples
+    --------
+    Query with padded Base32 string:
+    ::
+        SELECT from_base32('JBSWY3DPEBLW64TMMQ======'); -- [72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100]
+
+    Query with non-padded Base32 string:
+    ::
+        SELECT from_base32('JBSWY3DPEBLW64TMMQ'); -- [72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100]
+
+    Query with partially padded Base32 string:
+    ::
+        SELECT from_base32('JBSWY3DPEBLW64TM=='); -- Error: Base32::decode() - invalid input string: length is not a multiple of 8.
+
+    In the examples above, both fully padded and non-padded Base32 strings ('JBSWY3DPEBLW64TMMQ======' and 'JBSWY3DPEBLW64TMMQ') decode to the binary representation of the text 'Hello World'.
+    The partially padded Base32 string 'JBSWY3DPEBLW64TM==' will lead to a decoding error.
+
 .. function:: from_hex(string) -> varbinary
 
     Decodes binary data from the hex encoded ``string``.

velox/functions/prestosql/BinaryFunctions.h

@@ -386,6 +386,27 @@ struct FromBase32Function {
   }
 };
 
+template <typename TExec>
+struct FromBase32Function {
+  VELOX_DEFINE_FUNCTION_TYPES(TExec);
+
+  // T can be either arg_type<Varchar> or arg_type<Varbinary>. These are the
+  // same, but hard-coding one of them might be confusing.
+  template <typename T>
+  FOLLY_ALWAYS_INLINE Status call(out_type<Varbinary>& result, const T& input) {
+    auto inputSize = input.size();
+    size_t decodedSize;
+    auto status = encoding::Base32::calculateDecodedSize(
+        input.data(), inputSize, decodedSize);
+    if (!status.ok()) {
+      return status;
+    }
+    result.resize(decodedSize);
+    return encoding::Base32::decode(
+        input.data(), inputSize, result.data(), result.size());
+  }
+};
+
 template <typename T>
 struct FromBigEndian32 {
   VELOX_DEFINE_FUNCTION_TYPES(T);